January 19, 2010

I have two frickin' cool science articles to point out. The first one's simple and elegant. The second one is a little tougher to grasp but kinda awesome once you get it.

First up, a new mug that is designed to keep hot stuff hot - no keeping cool stuff cool here. It's based around the idea that materials hold their temperature during a phase change, and it's the same idea of the cool suits that mascots wear on the hottest days.

They start with something that's a solid at room temp and liquid at something just above cool body temp. Once they 'freeze' the materials (just the equivalent of a refrigerator temperature), it stays solid near their skin and starts to absorb energy. Once the material hits melting point - something near a comfortable temperature under the suit, the material will maintain that temperature for a fairly long time.

This group has designed a coffee cup filled with a material that has a melting point near that of comfortably hot coffee. Once the coffee cools to that temperature, the mug stays at that temperature for a much longer time than would a typical ceramic coffee mug. They've also worked on similar mugs designed to hold other beverages at cool or even icy temperatures.

Frickin' neat.

But not as neat as this article in which scientists found a way to have an inanimate object make its way through a maze based entirely on chemistry. No computer chips, no circuits, no robotic doomahitchies. Just chemistry.

They took an acidified oil drop and placed it in a maze. The oil drop found its way through the maze toward an acidified gel that was placed at the 'exit' of the maze. I'll let the article explain the science behind the whole thing as it's frickin' awesome...

Over the course of a minute or so, each droplet found its way to the end of the maze. The reason they move in the right direction has to do with basic chemistry. Acid from the highly acidic gel slowly leaks into the potassium hydroxide solution that fills the maze, creating a gradient: Solution near the exit becomes more acidic, whereas solution near the entrance stays more basic. This basic solution interacts with the acidic droplet, causing the part of the droplet facing the exit to become more acidic than the part of the droplet facing away from the exit. The disparity increases the surface tension of the side of the droplet that faces the exit--and it's this difference in surface tension between the two sides of the droplet that propels it toward the exit of the maze.

It's all impressive and stuff, but getting a droplet through a maze isn't anything to get exited about unless there was some way to make the process useful...like finding cancerous tumors which turn out to be more acidic than the environment around them.

Grzybowski notes that cancers are more acidic than the rest of the body, so--like the maze droplets--one could potentially design drug vehicles to follow the acid-base gradient toward the cancer cells.